Spoonarm: The deep sea super Mum

Lifecycle:

In the freezing waters of the Northern Atlantic resides an Octopus which spends a larger percentage of it’s life brooding for it’s young than any other species of Octopoda known. The Spoonarm (Bathypolypus arcticus) is a Deep Sea octopus that has been found as deep as 1,543 metres; typically it’s found between 200-600 metres. At these depths the average temperatures range in between 2-6 degrees celsius and the light level is almost non existent

The Spoonarm seems to be more devoted to reproduction than any other species in his genus, the male has the largest ligula compared to its body size of any octopoda; The ligula is a modified right arm from which the Spoonarm gets its name. This can be seen in the photo below. The modified arm is used in mating to transfer the spermatophores which are equally as large compared to the Spoonarms’ short body. Once the females eggs have been fertilised by the spermatophore she will then continue to care for the eggs for up to two years until they hatch. This already impressive feet is made even more impressive given that the average lifespan of B. arcticus is only three years.

The presiding theory of why any organism would have such a long brooding period is so that when the babies hatch they are developed enough to be completely self sufficient. Which when you are living in almost permanent darkness and freezing temperatures you need to be able to do whats necessary to survive.

What it eats:

This particular octopus has a very odd diet consisting mainly of brittle stars, which is an organism very similar to a starfish with five arms pointing out radially from a central disk. However many believe that this may just be due to food availability in the Spoonarms natural environment because in captivity they much prefer crustaceans and will actively seek out the latter if both are presented.

But why is it an extreme marine organism?

Not only does the Spoonarm live at such depths but it also lives at a very high latitudes, as a result it is exposed to extremely cold temperatures for most if not all of its life. Whilst humans have ways of adapting to both the cold and warm by adding layers, and using inventions such as air con. The cold blooded octopus has to just deal with whatever temperature it happens to swim into or which the current brings in its general direction. It lives in habitats so harsh that it will even resort to cannibalism which is rarely documented in the wild but thoroughly documented amongst those kept in captivity. And yet with all these trials and tribulation it has to go through just to exist it still manages to be one of the most prevalent deep sea predators as well as being one of the most prevalent species in its genus. showing not only that it is an extreme marine organism but that its not just a surviving like many other “extreme marine species” but it is actively thriving in an environment that up until about 400 years ago we thought could sustain nothing.

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Extreme marine habitats is a site dedicated to those habitats that are simply extreme! Written by students, we aim to provide detailed and insightful information on a variety of marine science subjects.